Early capturing and archiving of visible information, such as in static or moving pictures, was completed by exposing a light-sensitive medium to a focused image from a lens or lensing system. Static images were typically captured with a brief exposure period. Moving picture images were typically captured as a series of individual exposures or frames that, when played back in the same order, gave a viewer the appearance of motion.
Today, most images, both still and moving, are captured using arrays of solid state photo sensors, referred to as an active-pixel sensor (APS). The array captured images as an array of individual picture elements, referred to as pixels. In an APS, each image capturing element is associated with one or more photodetectors. For color imaging, elements may themselves be comprised of multiple photodetectors with each being sensitive to a particular range of visible light. By way of example, one detector may be used for respective primary colors to afford a gamut of colors in a captured image.
Digital image sensors a be comprised of CMOS sensors, NMOS sensors, charge-coupled devices (CCDs), thin film transistors, or the like. Early APS devices had fewer components or components that were less densely packed, resulting in relatively limited resolution. Continued advancement in APS design has resulted in images having a very high resolution achieved by very large arrays of photosensors. While increased resolution is advantageous for achieving better images, increasing a number of detectors requires a corresponding increase in power necessary to enable the image capture operation. This power increase can be particularly problematic when image capturing devices are portable or battery powered. Battery drain can be exacerbated when capturing video insofar as the photosensor array may be continuously or frequently enabled to capture a changed image or new frame.